Liquid transfer nanoimprint replication on non-flat surfaces for optical applications

Nanoimprint lithography offers unique capabilities to create patterns with three dimensional shapes. The challenge issue is therefore very often the method to create the stamp carrying complicated and high resolution pattern geometries in 3D. Especially when the geometry of the desired object exhibits a huge spectrum of spatial dimensions or if the replication has to be done on non-flat surfaces, standard mastering or imprinting techniques fail. By using liquid transfer nanoimprint the typical limitation of coating of non-flat surfaces processes is eliminated. We applied this process scheme on two very extreme topographies by creating anti-reflection textures on a micro lens array and a raw multi crystalline solar cell. The dependence between imprint pressure and deformation is analyzed. The results show that nanoimprint with flexible stamp can be extended to non-flat surface to created new sophisticated optical functionalities.

Figure optionsDownload as PowerPoint slideHighlights
► Demonstrations of the liquid transfer nanoimprint technique on non-flat substrates.
► Creation of hybrid micro optical elements with combined diffractive and refractive structures.
► Nanostructured moth-eye structure imprinted on a spherical micro lens array.
► Anti-reflection texture imprinted on a rough multi crystalline silicon solar wafer.