05 June 2017
Nanoimprint lithography (NIL) is one of the most promising technology platforms for generating 3D topographies by replication at micro- and nanometer scale with extremely high resolution and throughput. Commercial applications in micro-nano optics include diffractive and refractive optical elements, security features, micro-fluidics and life-sciences.
One of the remaining challenges of NIL is the fabrication of high quality 3D master originals – the initial single patterns that are replicated multiple times during mass production. In collaboration with micro resist technology GmbH, we have recently demonstrated how complex 3D topographies patterned by NanoFrazor lithography can successfully be replicated at high fidelity in a straightforward UV-assisted NIL process based on materials developed by micro resist technology. The sine wave pattern was first written into a NanoFrazor resist (polyphthalaldehyde, PPA) and then etched into a silicon substrate by reactive ion etching to form a 250-nm-deep silicon master original. In subsequent UV-NIL steps, the 3D topography was copied two times with high pattern fidelity into a polymeric intermediate stamp or working stamp (OrmoStamp®) and into the final optical polymer (OrmoClear®FX) retrieving the original pattern polarity.
This joint work demonstrates the possibility to transfer the unique NanoFrazor technology for master origination into high volume and large area production environments.