Fabrication of large area and precisely located nanostructures on silicon by interference lithography

Abstract

A combined top-down (interference lithography) and bottom-up approach (agglomeration of thin Au film) was developed to enable the placement of Au nanoparticles into a square array on silicon surface. The Au layer thickness and annealing temperature were varied to investigate the size tunability of the nanoparticles. Growth of silicon nanowires were carried out via the Vapor-Liquid-Solid (VLS) mechanism by using the Au nanoparticles as catalyst. The nanowires are of uniform diameter, but lack of orientational ordering. Next, a technique that made use of interference lithography and catalytic etching was developed to fabricate well-positioned one-dimensional (1D) silicon nanostructures array. The effectiveness of this technique in creating 1D silicon nanostructures with various cross-sectional shapes, diameters, and planar densities was examined. This technique was further extended to the fabrication of silicon nanocones. Finally, the silicon nanostructures were used as platform for the studies on cellular behavior under the influence of topographical cue.