Polymeric Nano- Templates and Nano-Structures
Producing a surface with an ultradense array of addressable nanoscopic elements that is perfectly ordered over macroscopic length scales is a formidable challenge. The self-assembly of block copolymers (BCP), two chemically dissimilar polymers joined together, is emerging as a promising route to generate templates and scaffolds for the fabrication of nanostructured materials, in particular in relation to their applications in nanowires, quantum dots, magnetic storage media, flash memory devices, photonic crystals, and silicon capacitors.
NanoImprint Lithography - NIL
NanoImprint Lithography (NIL) is a new method for macroscopic alignment of BCPs on molecular scale. It can be used as a tool for locally controlling the self-assembly of BCPs and determining the precise position of the phase-separated domains. Using numerical techniques, we investigate theoretically the role of important system parameters in producing well aligned BCP templates.
Chemically Nano-Striped Surfaces
Another way to control the structure of BCP films is by creating chemical nano-patterns on a silicon wafer and adjusting locally the various surface energies. This set-up is studied by us theoretically in collaboration with several experimental groups.
Electric Field Effects
Electric fields can be employed to re-orient and control morphology of BCP films. We study the role of added ionic impurities, as they have been shown to have a large effect on film morphologies.
Two steps of Nano-Imprint Lithography. A mold formed out of a grooved surface is pressed on a polymeric film (a). After temperature annealing, the mold is removed (b) and the film obtained a perfect inplane alignment.