Nanopatterning of metallic features over uniformed arrays of microbowl structures

Abstract

► An efficient nanofabrication technique based on nanosphere lithography and soft lithography is developed. ► Smaller interstitial spaces between spheres are achievable by self assembly of colloidal spheres over PDMS microbowls mould. ► Size of metallic patterns over PDMS can be tuned by either controlling metal deposition or using different spheres in size. ► Gold nanoparticles with perpendicular bisector of 210 nm and height of 50 nm were obtained in curvilinear triangular shape. ► The proposed nanofabrication process is suitable for volume nanopattern production at low costs. There is a growing interest for formation of periodic nanostructures in high-throughput and low-cost processes, due to their wide range of applications. This paper demonstrates a facile and efficient method to fabricate ordered gold nanopatterns over uniformed arrays of poly (dimethylsiloxane) (PDMS) microbowl structures by combining nanosphere lithography (NSL) and soft lithography. A monolayer of self-assembled polystyrene (PS) spheres is used as a template to create the PDMS microbowl structures. Another self assembly is processed on the PDMS mould followed by gold deposition, resulting in periodic pillars on the surface of microbowl structure. After removal of the microspheres, an array of highly ordered gold nanopatterns over hexagonal distributed pillars with perpendicular bisector of 210 nm and height of 50 nm in average are achieved. The geometry of the nanopillars with curvilinear triangle surface can be tuned by changing the size of spheres. This approach can be also extended to fabricate ordered periodic nanostructures of a wide range of metals (Pt, Ag, Cu, etc.) with controlled size.