Keywords: nanorods, nanorings, nanosphere lithography, colloidal lithography, shadow nanosphere lithography, 2D ordered nanoparticles, nanoparticle arrays, security, nanotechnology, nanostructures, interparticle apertures, lithographic masks, self-assembly, polystyrene latex spheres
A new method for production of nanoscale structures for possible applications in security
In this paper, we describe two different methods for decreasing the interparticle apertures in lithographic masks prepared by the self-assembly of polystyrene (PS) latex spheres. Such a modification is highly valuable for production of ultra-small islands by nanosphere lithography (NSL), or shadow nanosphere lithography (SNSL). The first method uses the overgrowth of SiO2 shells on the surface of PS. The second method uses heating of the PS latex mask near the melting point of polystyrene, causing the spheres to gradually melt together. Both techniques lead to a controlled, time dependent decrease of the aperture sizes in the mask.