We created hierarchical nanopores by prepatterning of the surface via nanosphere lithography (NSL) prior to a block copolymer lithography.
NSL is used in combination with reactive ion etching and subsequent physical vapor deposition of metals (Pt, Ti) in order to form a metal or semiconductor film with an antidot pattern, i.e. a hexagonally close packed arrangement of cylindrical holes. These antidots have typical diameters in the range of few hundred nm.
We then deposit the polymers and perform the microphase-phase separation for the creation of nanopores with tens of nm diameters. We analyze the influence of NSL pre-patterning on the microphase separation process in PS-b-PMMA block copolymers depending on the chemical and topographical morphology of the prepatterns.